Slidable fulcrum pliers



Nov. 22, 1955 c. L. OHMAN SLIDABLE FULCRUM PLIERS Filed Ma rch 22, 1954 IN VENTOR CARL L. OHMAN United States Patent Ofifice 2,724,300 Patented Nov. 22, 1955 1 2,724,300 SLIDABLE FULCRUM PLIERS Carl L. Ohman, Aldergrove, British Columbia, Canada Application March 22, 1954, Serial No. 417,833 2 Claims. (Cl. 8183) My invention relates to improvements in pliers.

The objects of the invention are to provide a plier of the adjustable range type having its leverage so compounded as to make it of particular advantage for use as a wrench or a pipe dog, whereby the plier may be capable of effecting a powerful grip upon its work and its jaws may be opened sufliciently to change its position on the facets of a nut by slightly relaxing the grip thereon, and also to provide that thrust upon one handle only will suffice to hold the jaws up to their work without slipping.

Referring to the accompanying drawings:

Figure 1 is an elevational view of the plier.

Figure 2 is a view of the swinging jaw and the hand lever showing connecting parts in dotted line.

Figure 3 is a sectional plan view taken on the line 3-3, of Figure 1.

Figure 4 is a sectional view taken on the line 4-4 of Figure 1.

Figure 5 is a sectional view taken on the line 55 of Figure 1.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral 1 indicates generally an upper jaw having a depending elongated shank 2, which is provided intermediate its length with an elongated slot 4, which slot is preferably disposed at an angle of ninety degrees from the nut gripping surface 5 of the upper jaw.

A groove 7, shown in dotted line in Figure 1, is formed on the inner face of the shank 2, which groove is relatively close to the pipe gripping portion 8 of the upper jaw and is preferably substantially parallel to the slot 4. While the slot 4 and the groove are shown as parallel to each other and at ninety degrees from the nut gripping surface 5 of the upper jaw, they may be somewhat out of parallel to each other and at a difierent angle to the nut gripping surface.

Coacting with the upper jaw 1 is a swinging jaw 9, see detail in Figure 2. This jaw is provided with a nut gripping surface 10 and a pipe gripping surface 11 and is provided with a pivot pin 14 which rides in the groove 7 of the upper jaw 1. The swinging jaw 9 is provided with a short shank 16 having a horizontal slot 17 intermediate its length and a substantially semi-circular gap or tooth root 19 at its lower end. A strut or hand lever 21, U-shaped in cross section, see Figures 1 and 2, is provided at its upper end with a cheek 22 extending upwardly on one side only, which cheek terminates in a semi-circular tooth 23 for the purpose of engaging the tooth root 19 of the swinging jaw 9. The tooth carries a fulcrum pin 24 which will be hereinafter referred to. The lower end of the U-shaped strut 21 is provided with a pair of trunnions 25 which engage an adjusting nut 26 which threadedly engages the lower end of the elongated shank 2 of the upper jaw 1.

A handle 30, shown in solid line in Figure 1 and in dotted line in Figure 2, is formed U-shaped in cross section to partly embrace the elongated shank 2 and is mounted upon a bolt 31 which passes through and rides within the slot 4 in the elongated shank and the horizontal slot 17 in the shank 16 of the swinging jaw 9. The handle is pivotally connected to the hand lever 21 by the previously described pin 24.

It will be clearly seen that by moving the adjusting nut 26 upwardly upon the elongated shank 2 that the strut or hand lever 21 will thrust the swinging jaw 9 upwardly relative to the upper jaw 1 and that the bolt 31 and the pin 14 will slide upwardly along the inclined slot 4 in the groove 7 respectively, thereby reducing the gap between said gripping faces 5 and 10. When a nut or other article to be turned is embraced by the opposing gripping faces and pressure is applied to the lever 21 and handle 30 to move them towards each other the thrust developed between the tooth 23 and the lower end of elongated shank 2 against the lower end of the swinging jaw 9 will impart to said jaw a slight upward movement lengthwise of the slot 4 and groove 7 and the movement of the handle to the left will impart a thrust through the tooth 23 to the lower part of the swinging; jaw shank 16, which will cause it to swing about the pin. 14 in a clockwise direction with the horizontal slot 17 moving to the left of the pin 31, thus said gripping jaw moves as a body lengthwise of the elongated shank of the upper jaw and simultaneously it describes with its gripping faces 10 and 11 an arcuate movement to close upon the work to be turned. When the handles are, after properly adjusting the nut 26, brought together to cause the work to be properly engaged or to the position shown in Figure 1, it will be noticed that the main fulcrum points, viz: the pin 14, the tooth 23, the pin 24 and the trunnions 25 will be in substantial alignment and that on account of the compounding of the leverages of the plier a very slight grip on the hand lever 21 and the handle 30 will be all that is necessary to maintain a proper grip on the work.

What I claim as my invention is:

1. A plier comprising an upper jaw having a gripping face and an elongated shank, said shank having a slot disposed at substantially right angles to said gripping face, a swinging jaw having a gripping face and a short shank, means connecting the short shank to the elongated shank to permit relative sliding movement of said shanks in a direction substantially parallel to said slot, said short shank having a slot intersecting the slot of the elongated shank, a hand lever pivotally connected at its lower end adjacent the lower end of the elongated shank, said hand lever being pivotally connected at its upper end to the lower end of the short shank, a handle pivotally connected adjacent its upper end to the upper end of the hand lever and a bolt secured to the upper end of the handle and slidably movable within the intersecting slots of the shanks.

2. A plier comprising an upper jaw having a gripping face and an elongated shank, said elongated shank having a slot disposed at substantially right angles to said gripping face, a swinging jaw having a gripping face and a short shank, said short shank having a pivot pin, said elongated shank having a groove disposed substantially parallel to said slot and in which the pivot pin of the short shank is slidably mounted, said short shank having a slot intersecting the slot of the elongated shank, a hand lever pivotally connected at its lower end adjacent the lower end of the elongated shank, said hand lever being pivotally connected at its upper end to the lower end of the short shank, a handle pivotally connected adjacent its upper end to the upper end of the hand lever, and a bolt secured to the upper end of the handle and slidably extending through the intersecting slots of the shanks.

References Cited in the file of this patent UNITED STATES PATENTS 148,889 Kotzum Mar. 24, 1874 1,145,067 Kelly July 6, 1915 1,373,683 Svebilius Apr. 5, 1921 1,448,238 Schmitz Mar. 13, 1923 2,496,308 Pugh et al Feb. 7, 1950 2,519,630 Boyer Aug. 20, 1950 2,574,909 Burrows Nov. 13, 1951 2,628,521 Berglund et a1 Feb. 17, 1953 

